#include<stdio.h>
int sum(int n)
{
    int i=1;
    int sum=0;
    for(;i<=n;i++)
    {
        sum+=i;
    }
    return sum;
}

int main()
{
    printf("hello linux!\n");
    int result=sum(100);
    printf("result=%d\n",result);
    return 0;
}
